The present invention relates to a family of novel multimetallic catalyst precursors and catalysts for use in the polymerization of olefins.
A variety of metallocenes and other single site-like catalysts have been developed to produce olefin polymers. Metallocenes are organometallic coordination complexes containing one or more pi-bonded moieties (i.e., cyclopentadienyl groups) in association with a metal atom. Catalyst compositions containing metallocenes and other single site-like catalysts are highly useful in the preparation of polyolefins, producing relatively homogeneous copolymers at excellent polymerization rates while allowing one to tailor closely the final properties of the polymer as desired.
Recently, work relating to certain nitrogen-containing, single site-like catalyst precursors has been published. PCT Application No. WO 96/23101 relates to di(imine) metal complexes that are transition metal complexes of bidentate ligands selected from the group consisting of: 
wherein said transition metal is selected from the group consisting of Ti, Zr, Sc, V, Cr, a rare earth metal, Fe, Co, Ni, and Pd;
R2 and R5 are each independently hydrocarbyl or substituted hydrocarbyl, provided that the carbon atom bound to the imino nitrogen atom has at least two carbon atoms bound to it;
R3 and R4 are each independently, hydrogen, hydrocarbyl, substituted hydrocarbyl, or R3 and R4 taken together are hydrocarbylene or substituted hydrocarbylene to form a carbocyclic ring;
R44 is a hydrocarbyl or substituted hydrocarbyl, and R28 is hydrogen, hydrocarbyl or substituted hydrocarbyl or R44 and R28 taken together form a ring;
R45 is a hydrocarbyl or substituted hydrocarbyl, and R29 is hydrogen, hydrocarbyl or substituted hydrocarbyl or R45 and R29 taken together form a ring;
each R30 is independently hydrogen, hydrocarbyl or substituted hydrocarbyl, or two of R30 taken together form a ring;
each R31 is independently hydrogen, hydrocarbyl or substituted hydrocarbyl;
R46 and R47 are each independently hydrocarbyl or substituted hydrocarbyl, provided that the carbon atom bound to the imino nitrogen atom has at least two carbon atoms bound to it;
R48 and R49 are each independently hydrogen, hydrocarbyl, or substituted hydrocarbyl;
R20 and R23 are each independently hydrocarbyl, or substituted hydrocarbyl;
R21 and R22 are independently hydrogen, hydrocarbyl, or substituted hydrocarbyl; and
n is 2 or 3;
and provided that:
the transition metal also has bonded to it a ligand that may be displaced by or added to the olefin monomer being polymerized; and
when the transition metal is Pd, said bidentate ligand is (V), (VII) or (VIII).
Similarly, PCT Application No. WO 97/02298, which is incorporated herein by reference, relates to a process for the polymerization of olefins, comprising contacting a polymerizable monomer consisting of ethylene, a norbornene or a styrene, with a catalyst system comprising the product of mixing in solution a zerovalent tricoordinate or tetracoordinate nickel compound that has at least one labile ligand, wherein all ligands are neutral, an acid of the formula HX, and a first compound selected from a group listed therein.
Also, PCT Application No. WO 96/33202, which is also incorporated herein by reference, relates to a transition metal catalyst containing pyridine or quinoline moiety having the formula: 
wherein Y is O, S, NR, 
wherein each R is independently selected from hydrogen or C1 to C6 alkyl, each Rxe2x80x2 is independently selected from C1 to C6 alkyl, C1 to C6 alkoxy, C6 to C16 aryl, halogen, or CF3, M is titanium, zirconium, or hafnium, each X is independently selected from halogen, C1 to C16 alkyl, C1 to C6 alkoxy, or 
L is X, cyclopentadienyl, C1 to C6 alkyl substituted cyclopentadienyl, indenyl, fluroenyl, or 
wherein m is 0 to 4, and n is 1 to 4.
Similarly, Fuhrmann et al., Inorg. Chem. 35:6742-6745 (1996) discloses certain Group 4 metal complexes containing amine, amido, and aminopyridinato ligands such as: 
wherein TMS is trimethylsilyl.
Also, U.S. Pat. No. 6,103,657, which is also incorporated herein by reference, teaches an olefin polymerization catalyst composition made from a heteroatom-containing precursor having the formula:
AqMLn 
wherein each A is represented by the formula: 
wherein M is a metal selected from the group consisting of Group 3 to 13 elements and Lanthanide series elements;
each L is a monovalent, bivalent, or trivalent anion;
X and Y are each heteroatoms;
Cyclo is a cyclic moiety;
each R1 is independently a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Groups 13 to 17 elements, and two or more adjacent R1 groups may be joined to form a cyclic moiety;
each R2 is independently a group containing 1 to 50 atoms selected from the group consisting of hydrogen and Group 13 to 17 elements, and two or more adjacent R2 groups may be joined to form a cyclic moiety;
Q is a bridging group;
each m is independently an integer from 0 to 5;
n is an integer from 1 to 4;
q is 1 or 2 and when q is 2, the A groups are optionally connected by a bridging group.
In one embodiment the catalyst precursor is represented by: 
wherein Ra and Rb are each independently selected from the group consisting of alkyl, aryl, heterocyclic groups, and hydrogen and Ra and Rb can be optionally connected to form a ring; Rc and Rd are each independently selected from the group consisting of alkyl, aryl, and hydrogen; and each L is a monovalent anion.
Although there are a variety of single site catalysts taught in the prior art, some of which are commercially available, there still exist a need in the art for improved catalysts and catalyst precursors that are capable of producing polyolefins having predetermined properties.
In accordance with the present invention there is provided catalyst precursors represented by the formula:
GgAnMmLp 
wherein M is a metal selected from Groups 1 to 15 and the Lanthanide series of the Periodic Table of the Elements;
g is an integer equal to or greater than 1;
m is an integer equal to or greater than 2;
each L is a monovalent, bivalent, or trivalent anionic ligand;
p is an integer equal to or greater than 1;
n is an integer equal to or greater than 2;
G is a spacing group that is capable of bonding to at least two A substituents; and
at least one A is selected from the following catalytically active ligands: 
M is included for convenience to show that it is bound to atoms X and Y.
G is also included for convenience to show that it can be bound to atoms X, Y, or bridging group of atoms T.
T is a bridging group containing 2 or more bridging atoms.
R can be a non-bulky or a bulky subsitutent. If it is a non-bulky substituent it will have relatively low steric hindrance with respect to X or Y and is preferably a C1 to C20 alkyl group. R can also be a spacing group as defined herein for G.
If R is a bulky group it will have a relatively large steric hindrance with respect to X or Y and be selected from the group consisting of alkyl (preferably branched), alkenyl (preferably branched), cycloalkyl, heterocyclic (both heteroalkyl and heteroaryl), alkylaryl, arylalkyl, and polymeric.
k is an integer that will vary to satisfy the oxidation state of xe2x80x9cXxe2x80x9d and will range from about 1 to 3. For example, when X is phosphorous k will be an integer from 1 to 3, preferably 2 for Structures I and 1 for Structures II. When X is nitrogen k is equal to 2 for Structures I and 1 for Structures II and when X is sulfur k is an integer from 0 to 3.
G is included for convenience.
Two or more of X, R, T, Y and G; preferably X, R, T, and G can be independently co-joined by single, hybridize, or multiple bonds if desired.